It is well known that diesel engines pose particular problems when operating in an atmosphere or environment containing natural gas or other volatile hydrocarbons. This often occurs in oil fields or chemical plants where engines, operating in and around a volatile fuel source, draw feral gas into the engine's intake manifold resulting in uncontrollable engine revving and possible catastrophic engine failure.
Numerous devices have been developed which interrupt either diesel fuel flow or air induction into the engine's air intake. Most of these devices require an external power source to either actuate an electric solenoid or to supply hydraulic pressure or are actuated manually with a cable. The present invention provides a diesel air intake shutoff device which operates fully automatically, uses no electrical wiring, no hydraulic plumbing and furthermore is easily retrofitted to an existing diesel engine.
The invention utilizes a valve assemble to shutoff the intake air between the engine's air filter and air horn or turbocharger. The valve is actuated by a trip mechanism controlled by engine vacuum on a regularly aspirated engine and controlled by a combination of engine vacuum and turbocharger pressure on a turbocharged engine.